Daveburt, The Super Computer thing was all mine. However my gateway motherboard manufactured by Foxconn C51GU01G1 is the stock mobo, all I've addes is the ATI X1900XTX, the PSU, and 2GB Memory (check My system specs). And keep in mind there are differences between the x1900xt and the x1900XTX. I spent 2 hours talking to ATI on the telephone until I got an answer as to the correct PSU 12v rail Amperage required. They reccomend an 18amp rail for standard single card operation. Any overclocking requires a 22amp rail, and Crossfire requires a minimum of 24 amp rail. Overclocking with x1900xtx crossfire they say 32 amp rail for max overclocking. Now I will also agree that there is a lot of confusion, partly due to the fact that not all PSU companys list AMPS PER RAIL; most only list TOTAL AMPS. Also the Amps listing on the ATI boxes are suposed to be Total AMPS of PSU but is not realy clear. This is what caused me to call ATI to begin with. Got sent up three levels of tech support before getting someone that made sense and knew what he was talking about. I have no problems at all with overclocking beyond Max.